1. Field
This invention relates to vehicle diagnostic equipment, including scan tools that analyze data streams, such as data streams that comply with the OBD II or EOBD data stream specifications. The invention more particularly relates to a vehicle diagnostic tool that is voice activated. Such a tool may be operated during a test drive of the vehicle being tested in a hands free configuration.
2. Description of Related Art
Vehicles, such as automobiles, often include numerous on-board computer systems. Each computer system often operates and tests various aspects of the vehicle, including aspects relating to the engine, anti-lock braking system (ABS), transmission and air bag. The number of on-board computer systems will vary from vehicle to vehicle but it is not intended within the context of the present invention to limit to any one number or numbers of such computers.
Scan tools are diagnostic devices that provide information about vehicles through interrogation of these on-board computer systems. An interrogation may seek one or more individual sensor data readings, such as a throttle, RPM or coolant temperature. Another interrogation may test for the setting of codes by the vehicle, such as a code indicating that there was an emission fault. A still further interrogation may cause the vehicle to perform a particular test and to return the results of that test.
Scan tools often communicate with the vehicle in accordance with an established communication specification, such as the OBD II or EOBD data stream specification, as will be appreciated by the person skilled in the art. Within the context of the present invention it will be appreciated that the two heretofore mentioned standards are exemplary of the type of vehicle ECU communication protocols that may be used to interrogate a vehicle electronic control unit. The diagnostic information that is returned from the vehicle may be displayed either in text or graphic format on a display associated with the scantool.
In order to diagnose a particular problem with the vehicle, the mechanic or technician must often determine which tests to administer and must analyze the diagnostic information that is returned as a result. Some scan tools assist the mechanic by allowing the mechanic to program the scan tool to begin recording diagnostic information when a particular condition is met, such as when the output of a sensor exceeds a pre-determined value. However, connecting a scan tool to a stationary vehicle in a workshop does not always give the mechanic a full diagnostic picture of the vehicle as some problems are only identifiable during normal driving conditions. It is therefore sometimes necessary for the mechanic to undertake a test drive of the vehicle. A diagnostic test drive is particular relevant when the technician is faced with an intermittent vehicle diagnostic problem or determining if a known issue has been fixed as most ECU's (Electronic Control Unit) will only store a fault code when a system or sensor fails. Intermittent faults will not be stored in memory and the only way to fully access a fault is to monitor the diagnostic PID (Parameter Identification Number) data while the vehicle is in motion and components and sensors are under load. Therefore as part of an optimum diagnostic process, technicians need to utilize a vehicle test-drive to determine and correct faults.
While recognizing that a vehicle test drive is a part of the diagnostic process, the problem is that heretofore no scan tool devices have been designed specifically to function safely during a vehicle test-drive with a single technician.
The dealerships are recommended by the vehicle OEMs (Original Equipment Manufacturer) to have two technicians in a vehicle for diagnostic test drives, this would allow one to concentrate on the scan tool data readings and while the other focuses on driving the vehicle. However, the reality is, and acknowledged by the manufacturers, that even in dealerships it would be prohibitively expensive for workshops to have two technicians doing a diagnostic test drive.
Furthermore, driving legislation is continuously evolving, where in-car distractions to drivers such as hand held mobile phones are no longer tolerated for safety reasons. Given the heavy traffic loads on roads no matter how skilled a technician any momentary distraction while analyzing a scan tool could easily result in an accident.
There is therefore a need for a scan tool that may be operated in test drive conditions by a single technician.